Substituted alpha-halogen alkyl tetrazoles and process for obtaining the same



Patented May 17, 1949 wsuns r-r'rurun 'ALPHAL'HAL'O'GEN' ALKY-L 'rE'rRAzoLEs AND raoons's'roaon- :TAINING THESAME Edward'lkfiriarvilh Orange,fandxRobert?M. firfit 'shdrif-flil'ls; N. J- .',assignors to E. Bi liulier, Incu,

Orange, N. J., atsorporation of New Jersey No Drawing. filpnwtion September 25, 194%, Serial N0. 618,580

'5 Claims. (013260 30 3) This invention, relates to new and valuable chemical compounds an "to the preparation thereof, said compounds comprising substituted alpha-halogen alkyl tetra'z'oles of the general formula:

wherein R1 is hydidatien, v autyi, aryl- :or aralkyl,

;1 :X isvchlorinerorbromine: and R2. is an .aryl; cycloalky1-,:alkyl or heterocyclic group such as pyridyl, lquinolyl isoquinoiyLetc.

This: application; is a continuation-impart of :our copend-i-ngiapplication Serial No. 546,7 31, filed These halogen tetrazoles areprepared rin "this inventionjfrom monosubstituted amides-20f alphahalogen acids of thegeneral formula wherein R1, R2 and X are as above defined, by causing hydrazoic .acid .qrl sodium azide to v react with the proauet rermeaty thefiinte'ra'ction 'of halides of'ifibi'gamc raoid'sjsuhas phosphorus I pentabhlo 'ride, an'a'the' substituted afiiide. Pre- V'lOllS ynthsesjldfiithi's type (i BraunnandlR uphosphorus pentachloride, or; substituted L' iniides containing a hydrogen "atom on th'elfalph'a carbon atom leads to the formation. of pha-chl'oro- 1 inc chlorides which react farmer tole'li'm'inate hydrogen chlorideandcpndense with themselves to form complegrducts (v. Braun, Josts, Heyman,B'r,' 60,"!!2;NlVf'Sidgwick, The Organic Chemistry of Nitrogen; p. 153, The Clarendon Press, Oxford, 1932).

'tcontrary'to theresu1teariticipated 611} the basis of experience reported in the'li ter'atu-reand cited above, we have found that the halides of inorganic acids, such as phosphorus pentachloride, may be caused to react smoothly withmono N-st ib'stitiut'ed alpha-halogenacid affi'ids *With the ter 'ation ei intermediateswhich-rat ieadily with hydrazoic acid or sodiumiazide toform-the desired substituted alphaeh alogen alkyl tetrazoles. Complex expected, in viewer-enema;

These alpha-halogen alkyl tetrazoles of our invention are valuable as intermediates in the preparation of therapeutically active tetrazole em arrass. the said ,.:v m/c-s-nm' 'atom in the compounds es the reactions typical benzene solution tr 23'v of hy aoio racid. After 'the'i'i iitial'reactioh 'had s'i'd'ed, tholution was refluxed dntilgth'e evolution of hydrogen The benzene was removed w'ai'ter. From. the 0.5% bf theory) .pf

1-pher1yl-5-ch1oro t he was 'is'ol ated as a colorless, 'crysta e the e lproduct was purified by recrystallization train tartan tetra chloride. M. P. "Is-7W0.

dissolved with 118 rains "g When the reaction'wvas'rcompietd,"the benzene and phosphorus oxychloride were removedya-ben- 'zene solutio'n -df t33 'grams of 'hyd'i'azoic acid was added to the residue and the iniiit'ur'e "refluxed fiuntil hydrogen chloride evolutiohhad ceased. 127

grams of 1-phenyl-5-alpha-bromo=ethyl tetrazole was obtained/from the reaction mixture in the manner describedwin Examplell 'I-heptetrazole separated fromz aque'ous ;"methylalcohol "as a crystalline material. P. 98 C.

g From 165 gramsof alphabromoisoyaleranilide and 118 grams of; phosphorus pentachloride; 156 grams of e hen ral turbr m sqeetrl; e razole was obtained by following the procedure des ri d i Ex ple- .2; il e wnd -errstallized from a mixture of thyl'ether-petroleum ether. M. P. 72.5-73.5 C.

Example 4 grams of alpha-ch1oroacetnaphthalide was added to 800 cc. of anhydrous benzene. Phosphorus pentachloride (124 grams) was added at room temperature after which the mixture was kept at this temperature until a clear solution formed. A benzene solution of 32 grams of hydrazoic acid was added and the solution was warmed at 50 C. until hydrogen chloride evolu tion had ceased. The solvent was removed and the residue was refluxed with water. From the mixture 85 grams of 1-alpha-naphthyl-5-chloromethyl tetrazole was obtained. The pure compound was isolated as a colorless crystalline material from aqueous methanol. M. P. 103-10 0. Calculated: N=22.95%. Found: N=22.75%.

Example 5 '72 grams of N-benzyl chloroacetamide in 500 cc. of anhydrous benzene was treated with 81 grams of phosphorus pentachloride at room temperature. When the reaction was completed, 18 grams of hydrazoic acid in benzene was added to the clear solution and the homogeneous mixture was warmed to 50 C. until hydrogen chloride evolution had ceased. The solvent was removed and the residue was recrystallized from 50% methanol. From the cooled solution l-benzyl-5-chloromethyl tetrazole was obtained as a fine colorless crystalline material. M. P. (ST-68 C. Yield 46 grams.

Example 6' From 49 grams of N-methyl chloroacetamide and 9 1.5 grams of phosphorus pentachloride, 21 grams of l-methyl-5-chloromethyl tetrazole was obtained by following the procedure described in Example 4. The pure compound crystallized from ethyl ether. M. P. 65.066.5 C.

Calculated: N=42.26%. Found: N=42.08%.

Example 7 From 82 grams of N-cyclohexylchloroacetamide and 97 grams phosphorus pentachloride, 75 grams of 1-cyclohexyl-5-ch1oromethyl tetrazole was obtained by following the procedure described in Example 4. crystallized from aqueous methanol. M. P. 108.5-109 C.

Calculated: N=28.00%. Found: N=27.93%.

By application of the above procedures to the appropriate substituted amides, the following halogen alkyl tetrazoles have been prepared and are cited by way of examples, but the scope of our invention is not limited thereto:

The pure compound 4 1-benzyl-5-chloromethyl tetrazole. M. P. 67-68 We claim:

1. A process for the manufacture of substituted halogen alkyl tetrazoles of the general formula wherein R1 is a member selected from the group consisting of hydrogen and alkyl, R2 is a member selected from the group consisting of aryl, cycloalkyl, alkyl and aralkyl, and X is a, member selected from the group consisting of chlorine and bromine which consists of causing a mono-N-substituted alpha-halogen acid amide of the general formula R2.NH.C:O.CH(R1) .X wherein R1, R2 and X are as above defined, to react with a phosphorous halide at a temperature sufficiently low to prevent alpha-halogenation, and treating the product so formed with a compound of the group consisting of hydrazoic acid and sodium azide.

2. The new and useful substituted halogen alkyl tetrazoles of the general formula R1 Rz-NC--J1HX wherein R1 is a member selected from the group consisting of hydrogen and alkyl, R2 is a member selected from the group consisting of aryl, cycloalkyl, alkyl and aralkyl, and X is a member selected from the group consisting of chlorine and bromine.

3. The compound 1 phenyl 5 chloromethyl tetrazole.

4. The compound l-phenyl 5 alpha-bromoethyl tetrazole.

5. The compound l-a-naphthyl-5-chloromethyl tetrazole.

EDWARD K. HARVILL. ROBERT M. HERBST.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 287,924 Great Britain July 16, 1929 576,327 Germany May 10, 933

OTHER REFERENCES Berichte, vol. 63, 1930, pp. 498-502. Copy in Scientific Library-Patent Oflice.) 

